Cardiac rhythm management devices can include implantable or ambulatory devices, such as pacemakers, cardioverter defibrillators, or devices that can monitor one or more physiological parameters, and/or provide one or a combination of pacing, defibrillation, and cardiac resynchronization therapies. Such devices can be configured for use with a plurality of implanted or external electrodes, such as to detect or treat cardiac conditions. These electrodes may be configured in a plurality of different combinations for sensing cardiac electrical activity or delivering electrical stimulation therapy. Using different combinations of electrodes for sensing cardiac electrical activity may produce different sensed signals. Using different combinations of electrodes for delivering electrical stimulation therapy may result in different effectiveness of the therapy. Each of these electrode configurations may be termed “vectors.” Selecting a proper vector for sensing cardiac electrical activity and/or for delivering electrical stimulation therapy can help ensure more effective treatment. However, in some systems, the number of available vectors is large due to the number of implanted electrodes. In such systems, assessing each vector in order to select one or more vectors for sensing and delivering electrical stimulation therapy may be time consuming, and in some cases bothersome to the patient.